666140400 has 360 divisors, whose sum is σ = 2456223744. Its totient is φ = 166924800.

The previous prime is 666140383. The next prime is 666140417. The reversal of 666140400 is 4041666.

It is an interprime number because it is at equal distance from previous prime (666140383) and next prime (666140417).

It is a tau number, because it is divible by the number of its divisors (360).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 5245137 + ... + 5245263.

Almost surely, 2^666140400 is an apocalyptic number.

666140400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666140400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1228111872).

666140400 is an abundant number, since it is smaller than the sum of its proper divisors (1790083344).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666140400 is a wasteful number, since it uses less digits than its factorization.

666140400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229 (or 215 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 666140400 is about 25809.6958525280. The cubic root of 666140400 is about 873.3505360842.

The spelling of 666140400 in words is "six hundred sixty-six million, one hundred forty thousand, four hundred".